Supercharger with controllable inlet



Nov. 25, 1947. A. HASBROUCK 2,431,398

SUPERCHARGER WITH C ONTROLLABLE INLET Filed Aug. 22, 1944 IN V EN TOR.

Patented Nov. 25, 1947 SUPERCHARGER WITH CON TROLLABLE INLET Augustus Hasbrouck, Middletown, Conn., assignor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application August 22, 1944, Serial No. 550,655

7 Claims.

This invention relates to superchargers for internal combustion engines and has for its object to provide a novel and improved device of this type with means for varying the supply of air to the engine.

Another object of the invention is to provide means for throttling the entrance to a supercharger in such a way as to insure the symmetrical distribution of air to the impeller under all conditions of throttling and loading.

Another object is to vary the amount of air pumped by a supercharger by varying the inlet area of the system, and at the same time provide a beneficial pre-rotation of air as it enters the impeller.

Still another object is to provide a simple and efficient supercharger of the foregoing type having novel and improved details of construction and features of operation.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

In the embodiment of the invention disclosed herein for'purposes of illustration, I vary the amount of air pumped by a supercharger by providing a movable baffle or piston to vary the inlet area of the supercharger. The intake air passes between a stationary wall and the movable piston, and, as the piston is moved with respect to said wall, the intake area and consequently the amount of intake air is varied.

The control means for the piston may comprise, for example, a rotatable shaft acting through suitable gears to rotate a spur gear meshing with teeth on the piston. To translate the resulting rotary movement of the piston into axial movement, helical threads or splines are provided between the piston and a stationary hub on which the piston is mounted.

A particular advantage of my improved construction is that it insures the symmetrical distribution of air to the impeller under all conditions of throttling and loading. non-turbulent flow is obtained because a Venturilike shape for the inlet passage is maintained at all throttle, or control lever, positions. Smooth throttle or control lever operation is insured. by the provision of means for equalizing the pressure on opposite sides of the piston, thus maintaining the force required to move the same substantially constant.

Although the novel features which are characteristic of this invention are set forth more in detail in the claims appended hereto, the nature and scope of the invention may be better under- Substantially.

2 stood by referring to the following description, taken in connection with the accompanying drawing forming a part thereof, in which a specific embodiment has been set forth for purposes of illustration.

The drawing is a schematic vertical sectional view illustrating a supercharger constructed in accordance with the invention.

In the following description certain specific terms are used for convenience in referring to the various details of the invention. These terms, however, are to be interpreted as broadly as the state of the art will permit.

The drawing shows the casing 5 of an internal combustion engine, within which is journaled a shaft 6 carrying the impeller I. The shaft 6 is driven by the engine, or by the exhaust gases, in any suitable manner well understood in the art.

An air inlet passage 8 communicates with the intake chamber 9 which has a stationary Venturishaped wall ID. The blades of the impeller 'I make a close running fit with the Venturi-shaped wall Ill which leads through a passage containing the usual stationary directional blades I2 to the inlet manifold I3.

The intake chamber 9 contains a, stationary cylindrical hub or drum I4 in axial alignment with the impeller shaft 6. Mounted on the hub I4, and movable axially thereof, is a bafile or.-

piston I5 having a cylindrical skirt l6 telescoped within the cylindrical wall ll of casing 5, and a front wall 18 suitably shaped to direct the air in chamber 9 to the impeller. The skirt l6 of the piston is preferably provided with piston rings I9 engaging the cylindrical wall II of the casing for sealing purposes.

The piston I5 is actuated by a control lever 2| carried by a rotatable shaft 22 journaled in casing 5. Shaft 22 carries a bevel gear 23 meshing with a similar gear 24 on shaft 25 which also carries a spur gear 26 meshing with teeth 21 on the piston l5 to rotate the latter. This rotary movement of the piston I5 is translated into axial movement by means of cooperating helical threads or splines 28 on the piston and the stationary hub M, as shown in the drawing.

Accordingly, whenever the control lever 2| is actuated, the piston I5 is moved axially upon the hub I4, either toward or away from the stationary Venturi-shaped wall l0 depending upon the direction of movement of the control lever. In the position shown in full lines in the drawing the control lever 2| is in its open position, and in this position the piston I5 is withdrawn the maximum distance into the cylindrical 'wall II of the casing. However, when control lever 2lis moved to the dotted line position shown in the drawing, the piston I5 is moved outwardly to its maximum limiting position adjacent the wall in as indicated ,throttle or control lever positions, with resulting symmetrical distribution of air to the impeller under all conditions of throttling and loading. The foregoing construction also results in a beneficial pre-rotation of air as it enters the impeller. Heretofore, such uniformity of distribution and pre-rotative effect have been obtainable only by using an axial inlet, and limits on engine length have precluded the possibility of suflicient length of axial inlet to accomplish any beneficial result.

In the embodiment illustrated, smooth throttle or control lever operation is insured by the provision of balance holes 30 in the front wall l8 of the piston to equalize the air pressure on opposite sides of the piston, thus maintaining the force required to move the same substantially constant.

A plurality of holes 3i in the annular throat of the Venturi wall In open into an annular passage 32 which is connected to an air duct 33 which may be utilized to provide the suction side of the metering differential for a pressure type carburetor. The static side of such difierential may be connected to any suitable point upstream from the annular Venturi throat.

Although a specific embodiment has been shown and described herein for purposes of iilustration, it will be evident to those skilled in the art that numerous modifications and adaptations may be made without departing from the scope and spirit of the invention as defined in the appended claims.

What is claimed is:

1. A supercharger for internal combustion engines comprising an air intake chamber having a stationary Venturi-shaped wall, a rotary impeller in said chamber, a, stationary cylindrical hub in said chamber in axial alignment with said impeller, a piston movably mounted on said hub and cooperating with said stationary wall to direct the air in said chamber to said impeller,

- means for imparting rotary movement to said piston, and means for converting said rotary movement of said piston into axial movement thereof to vary the effective intake area of said chamber.

2. A supercharger for internal combustion engines comprising an air intake chamber having a stationary Venturi-shaped wall, a rotary impeller in said chamber, a stationary cylindrical hub in said chamber in axial alignment with said impeller, a piston movably mounted on said hub and cooperating with said stationary wall to direct the air in said chamber to said impeller, means for imparting rotary movement to said piston, and cooperating helical threads on said hub and said piston for converting rotary movement of said piston into axial movement thereof to vary the effective intake area of said chamber.

3. A supercharger for internal combustion engines comprising an air intake chamber having a stationary Venturi-shaped wall, a rotary impeller in said chamber, a stationary cylindrical hub in said chamber in axial alignment with said impeller, a piston movably mounted o said hub and cooperating with said stationary wall to direct the air in said chamber to said impeller, means for imparting rotary movement to said piston, cooperating helical threads on said hub and said piston for converting rotary movement of said piston into axial movement thereof to vary the effective intake area of said chamber, and means for equalizing the pressure on opposite sides of said piston to maintain the force required to move same substantially constant.

4. A supercharger for internal combustion engines comprising an air intake chamber having a stationary Venturi-shaped wall, a rotary impeller in said chamber, a stationary cylindrical hub in said chamber in axial alignment with said impeller, a piston movably mounted on said hub and cooperating with said stationary wall to direct the air in said chamber to said impeller, means for imparting rotary movement to said piston, and cooperating helical threads on said hub and said piston for converting rotary movement of said piston into axial movement thereof to vary the effective intake area of said chamber, said piston containing balance holes to equalize the pressure on opposite sides thereof,

5. A supercharger for internal combustion engines comprising an air inlet chamber having a circular depression in the end wall thereof, a stationary threaded hub anchored in said end wall, a piston on said hub having grooves engaging the threads of said hub and movable into adjusted positions in said depression, a revoluble shaft extending into said chamber in alignment with said hub and having an impeller thereon and a Venturi wall surrounding said impeller.

6. The supercharger of claim 5 in which said Venturi wall is provided with a pluarlity of holes in the throat thereof.

7. The supercharger of claim 5 in which said Venturi wall is provided with a plurality of holes in the throat thereof and an air duct is connected to an annular passage into which said holes extend.

AUGUSTUS HASBROUCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 860,668 Jaeger July 23, 1907 1,011,313 Bretherick Dec. 12, 1911 1,517,329 Weiss et al. Dec. 2, 1924 1,813,747 Kirgan July 7, 1931 1,834,959 May Dec, 8, 1931 1,858,071 Chester May 10, 1932 2,083,184 Anderson June 8, 1937 2,143,100 Anderson Jan. 10, 1939 2,156,405 Smoot May 2, 1939 2,188,547 Anderson Jan. 30, 1940 2,357,527 Lundquist Sept. 5, 1944 2,405,282 Birmann Aug. 6, 1946 FOREIGN PATENTS Number Country D te 346,968 Great Britain Sept. 30, 1930 576,643 Germany May 27, 1933 

